An apparatus coupled via an interface according to a standard related to supply of power source currents is supplied with a power source current. As being connected via the interface according to the standard possibly without an embedded battery, an AC power source or the like, the apparatus may be downsized or be trimmed weight. A personal computer (PC) or something may be provided with a plurality of interfaces according to the standard related to supply of power source currents. A system for supplying the PC with a power source current via the interface may be installed on the PC.
A related art is disclosed in Japanese Laid-open Patent Publication No. 2009-75902 and International Publication Pamphlet No. WO 2005/022369.